Locking device for removable points for earth-working tooth units



Sept. 16, 1952 A. N. CRAWFORD 2,610,417

LOCKING DEVICE FOR REMOVABLE POINTS FOR EARTH-WORKING TOOTH UNITS Filed Jan. 28, 1949 flrZb ur M C'ra wrford ATTORN EYS Patented Sept. 16, 1952 U IT-so STATES PATENT OFFICE,

LOCKING DEVICE FOR REMOVABLE nom'rs Fon EARTH-WORKING 'roo'rn UNITS N. Crawford, Hermosa Beach, Calif. Application January 28, 1949, Serial No. 73,385

a locking device, for the purposedescribed, which includesa key extending through the removable, K

socketed -point' and the adapter tongue engaged therein; there being a"novel spring assembly working against said key, intermediate its ends to maintain the pointin'place.

An additional object'of the invention-is to provide a locking device, as in theprecedingparagraph, wherein said spring assembly includes a heavy-duty compression spring extending lengthwise of the tooth unit and working against the forward edge'of the. key: such spring being disposed in an internal bore formed in top-part in the under surface of the blade of the point and in bottom-part in the upper surface of the adapter tongue. This bore is arranged so as to permit of unrestricted movement of the point onto theadapter tongue, with the spring first seated in the bottom part of said bore.

5A further. object of the invention is to provide lOlaim. (01. 37-142) a loekingdevice for removable.- point earthworking unit which is designedfor-ease and economy of manufacture. v

Still another object of the invention is to provide a locking device, for the purpose, which is practical and reliable, andyet is exceedingly effective for the purpose for which it is designed.

These objects are accomplished by means of such structure and relative arrangement of parts as will fully appear by a perusal of the following specification and claims.

Inthe drawings:

Fig. l is a perspective view of a removable point tooth embodying the invention; the parts being illustrated in adjacent but separated relation.

Fig. 2 is a side elevation, partly in section, with the parts separated as in Fig. 1.

Fig. 3 is a fragmentary sectional plan on line 33 of Fig. 2.

Fig. 4 is a side elevation, partly in section, of the tooth unit with the parts engaged and locked together for use.

Referring now more particularly to the characters of reference on the drawings, the improved locking device is embodied in a tooth unit of the type which includes an adapter I which comprises a body '2 provided with means (not shown) for'securing such adapter to a mounting part, such as the bottom lip of a dredge bucket or the supporting bar of a scarifier.

The body 2 is substantially rectangular in cross section and is formed, at the front, with a forwardly projecting tapered tongue 3; the cross sectional configuration of the tongue 3 being symmetrical to, but smaller than, the body 2, whereby to form forwardly facing side stop shoulders 4, a top stop shoulder 5, and a bottom stop shoulder 6; said top stop shoulder 5 being formed slightly rearwardly of the side stop shoulders 4.

The removable point of the tooth unit is indicated generally at 1, and such point includes, at thetop, a relatively heavy or thick blade 8 sharpened at the front end to form a cutting or digging edge 9. The removable point I additionally includes, below the blade8, a rearwardly opening taper socket l0 adapted to receive the tongue Sin matching relation; thecorresponding rear end parts of the removable point 1 then being substantially in engagement with the stop shoulders 4, 5, and 6. A pair of transversely spaced, rectangular bosses H project rearwardly from the rear end of the blade Band normally engage in matching sockets I2 formed in the top stop shoulder 5; such rectangular bosses H being provided to stabilize the removable point 1 when engaged on the tongue 3. v v V The removable point 1 is normally secured in connection with the adapter I by means of the following locking device:

Adjacent, but short of, its rear end the point 1 is formed with a transverse keyway 13 which opensthrough opposite sides of said point, and

-is formed in the main inthe blade 8, opening downwardly therefrom.

At a, point intermediate the ends of the tongue 3 the tooth unit is formed with an internal longitudinal bore, indicated generally at M, which longitudinal bore is comprised of a lower recess or groove I5, half-circle in cross section, cut in the top of the tongue 3, and a longitudinal upper recess or groove l6, half-circle in cross section, formed in the under side of the blade 8, such grooves matching so that the resultant bore It is circular in cross section.

The lower groove l5 terminates short of the rear end of the tongue 3 while the upper groove [6 extends rearwardly to, and is open at, the rear end of the blade 8 between the rectangular bosses, for the purpose hereinafter described.

The forward end of the internal longitudinal bore is disposed some distance ahead of the keyway I3; the latter intersecting such bore at the rear end portion of the lower groove IS.

A heavy-duty compression spring I! is initially seated in the lower groove l5 and the upper groove is open to the rear end of the blade 8 for the purpose of permitting the tongue 3 to move into the taper socket l0 without obstruction by the portion of the spring I! which extends above the upper surface of the tongue 3. Additionally, the internal longitudinal bore [4 pitches forwardly and downwardly slightly so as to further facilitate entry of the tongue 3 into the socket l0 without interference by the projecting portion of said spring l7.

When the tongue 3 is thus engaged in the socket H], a key I8 is driven through the transverse keyway I3, such key including a tapered lead or tip l9 which guides the key to position; such tip projecting beyond the tooth unit and being adapted to be broken off by a hammer blow. A scored line 28 between the tip 19 and key I8 is provided so that said tip will break off easily.

When driven to place in the transverse keyway 13 the key l8 bears forcefully against a round head 2| on the adjacent end of the spring ll, which head 21 is located in place by means of an axial stem 22 which projects into the spring. The key is recessed, as at 23, to matchingly receive the head 2! With the key I 8 in place, and the spring I! under load, the spring acts on the key to urge the removable point I rearwardly or inwardly to hold it in place on the tongue 3 and in proper engagement with the described stop shoulders.

A pair of key-stop lugs 24 upstand from the top of the tongue 3 ahead of the key [8 when the latter is in position in the tooth unit; there being downwardly opening pockets 25 in the blade 8 to receive such lugs, and said pockets being in communication with both the keyway l3 andthe bore [4. (See Fig. 3.) The key-stop lugs 24 prevent the key l8 from imposing too great a load on spring I! when the tooth unit is in use and when-at certain timesthe removable point 1 tends to work outward slightly on the tongue 3.

When the described locking device is in use, the removable point 1 is securely and effectively maintained in place on the tongue 3 of the adapter I the arrangement being shock-proof and of 4 such construction as to withstand the great working strain placed on a tooth unit of earth working type. Yet, when the point 1 is worn, it can be readily and easily removed by driving out the key l8 and then separating said point from tongue 3; the upper portion of spring I! then relatively moving along, and out of, the upper longitudinal groove I6.

From the foregoing description it will be readily seen that there has been produced such a device as sbstantially fulfills the objects of the invention, as set forth herein.

While this specification sets forth in detail the present and preferred construction of the device, still in practice such deviations from such detail may be resorted to as do not form a departure from the spirit of the invention, as defined by the appended claim.

Having thus described the invention, the following is claimed as new and useful, and upon which Letters Patent are desired:

In an excavating tooth which includes an adaptor body having a forwardly projecting tapered tongue, and a tooth point having a rearwardly opening tapered socket to fit over the tongue in matching relationship; a longitudinal closed-end substantially semicircular groove in the upper surface of the tongue intermediate the ends thereof, a complementary groove formed in the upper inner surface of the socket and opened to the rear end thereof, the tongue groove and the forward portion of the socket groove being disposed in matching relationship when the socket is fitted over the tongue,a transverse key slot in the socket intersecting the groove therein and having its lower edge flush with said inner surface of the socket and positioned to overlap the rear end of the tongue groove when the tongue is fitted in the socket, and a helical compression spring fitted in the tongue groove and initially extending from end to end thereof whereby the rear end portion of the spring then projects into the key slot; there being a key for insertion into said key slot.

ARTHUR N. CRAWFORD.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,307,359 Crawford Jan. 5, 1943 2,312,802 Crawford Mar. 2, 1943 2,427,651 Baer Sept. 23, 1947 

